In 2025-26 it enrolled 362 students across grades PK–8. That is 67 fewer than in 1998-99 (429) — the district has shrunk. It peaked at 479 in 2001-02. Its biggest cohort is grade 3.
Students enrolled in each grade each fall, stacked to the total — so the top edge is total enrollment. Bands run from the lowest grade (light) to the highest (dark); a band that appears or disappears is a grade the school added or dropped. “Other” is students with no grade level (mostly special education), so the bands always sum to total. Source: NJDOE Fall Enrollment.
The largest group in both 1998-99 and 2025-26 was White students — 91% then, 44% now.
Each group’s share of enrollment over time, or its head count — toggle above. New Jersey expanded race and ethnicity reporting from five to seven categories in 2006-07 (dashed line), so “two or more races” appears only after; Asian here includes Pacific Islander. Source: NJDOE Fall Enrollment.
Between 2021-22 and 2025-26 the makeup of this district shifted noticeably.
The index is half the sum of every group’s change in share, on a 0–100 scale (how it works). Compare any two years in the explorer →
In 2025-26, 24.9% of students qualified for free or reduced-price lunch.
Share of students eligible for free or reduced-price meals. The lighter line shows Morris County, for comparison. Not reported by the state in some years (shaded). Since 2014, some districts provide free meals to all students regardless of household income, which can lift the eligible share. Source: NJDOE Fall Enrollment.
In 2025-26, Mount Arlington proposed a $16.2 million General Fund operating budget.
These are proposed NJDOE User-Friendly Budget planning rows—not audited actuals, household tax bills, or all-funds totals.
Growth measures how much students progressed over the year against peers who scored the same the year before — 50 is a typical year. In 2024-25, this district’s median growth percentile was 58.5 in English and 64 in math — NJ calls this “typical” growth.
English language arts: 69.3% met or exceeded expectations in 2024-25 (state 53%), up from 63.5% in 2021-22.
By grade, year to year
Each panel is one grade — watch its mix of levels shift across 2021–2024.
By grade cohort, lined up across years
Each panel lines up aggregate grade results one grade higher each year. It approximates a class cohort, but does not track individual students; enrollment can change.
Math: 49.1% met or exceeded expectations in 2024-25 (state 42%), up from 42.5% in 2021-22.
By grade, year to year
Each panel is one grade — watch its mix of levels shift across 2021–2024.
By grade cohort, lined up across years
Each panel lines up aggregate grade results one grade higher each year. It approximates a class cohort, but does not track individual students; enrollment can change.
In each panel the flat line is the proficiency boundary: levels 4–5 (met or exceeded) fill the area above it, levels 1–3 below — so a smaller reported share in levels 4–5 makes the area above the line shrink (it isn’t a misleading upward slope). Light = level 1 (did not yet meet expectations), dark = level 5 (exceeded); the % marks the proficient share at the first and last points. The first set of panels follows each grade across the years; the second lines up aggregate grade results one grade higher each year. It approximates a class cohort, not linked individual students. Growth is the median Student Growth Percentile (50 = a typical year), reported only through grade 8. The NJSLA was not given in spring 2020 and was disrupted the next year. Source: NJ School Performance Reports.
In 2024-25, 14.2% of students were chronically absent — missing at least 10% of school days — down from 19.1% in 2021-22.
Chronic absenteeism — the share of students who missed 10% or more of the days they were enrolled (roughly 18 days across a full school year). The lighter line shows New Jersey, for comparison. Source: NJ School Performance Reports, 2024-25.
The district’s 2 schools on record. Open any for its full profile.
Profile built from New Jersey Department of Education Fall Enrollment data, 1998-99 through 2025-26. How this data works →
